Pavement



1,623,417 Aprll 5, 1927. F V. LANHAM PAVEMENT Filed Jan. 7, 1927 2Sheets-Sheet 1 I more permanent structure.

UNITED STATES PATENT. OFFICE.

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v i Application filed January 7, 1927. Serial No. 159,514.

This invention relates to new and useful invention will be hereinafterdescribed, to- I improvements in pavements. gether with other featuresof the invention. It is well understood that horse-drawn ve- Theinvention will be more readily under 'hicles do not create such severeand dete stood from a reading of the following specino rioratingconditions uplon roadways as are fication and by reference to theaccompan imposed by motor ve icle traffic and the ing drawings, in whichan example oft e present invention has to do with a pavement Invention1s shown and wherein: designed, laid, and composed of m terials Fig. 11s a transverse sectional view of capable of withstanding such motor vhicle the sub-grade upon which the concrete e5 traflic and the loadsincident thereto. foundation has been laid, One object of the inventionis to provide Fig.2 is a similar view with the rocks or a pavement inwhich the rigidity, solidity, stones spread on the foundation and readyand strength of concrete pavement will be for 1mbedd1ng, obtained. F1 3is a similar view showing the rocks 16 I Another object of the inventionis to proimbe ded to substantially half their divide a avement in whichthe major portion meter, of-the investment is not subject to replace-Flg. 4 1s a similar view of the completed. ment, thus requiring onlyfaminor financial pavement, investment in that portion of the pavement,Fig. 5 1s an isometrical view of a portion which is subject to repair.8 f a pavement constructed in accordance It has been the practice "inthe laying of l h my Invention and before the filler has pavements topartially imbed small stones or n applied, and j rocks in the surface ofa cement course and F g. 6 is asimilarview after the filler has toutilize the upwardly projecting portions beell'a P -l $3 of the stonesto bond a to layer onto the In t e drawings the numeral 10 designatescement course. However, t e to course has th 1 81 sub-grade, which isproduced in acalways been given considerab e thickness rdance with theusual practice in this art. and is known as the wear la of the Curbs orhinder wallsll are provided along pavement. The top, or wear layer, ismore a h side of the sub-grade, as is shown in 85 or less ex nsive toconstruct and replace. g- 1- Agconcrete foundation -12, of such Aparticular object of the invention is'to r ngthig-and' thickness as tosupport the provide a wear layer composed of stones or loads which thestreet or highway is to. carry, rocks, partially imbedded in the surfaceof {sh-1d onthe sub-grade IOand m .the course on which the wear layer issupernforced with metal if desired. SI imposed, whereby said stones orrocks will ents and consistency-inf the foul may,

take the wear directly and substantially. vary in accordance with the 1A further object of the invention.1s' to accordance with whichthe pafill the voids or interstices between the probuilt. jections of thestones with a filler having its While the concrete foundati green 98 40upper surface substantially flush with the. and prior to its initialset, a

highest points of the projecting stones, mg of hard broken or crushed wereby a smooth and easing surface is 13 is uniformly-spread inclosecontact over presented. It is prefera Is to use a bitu the topsurface of the foundation. It is' (I, and pleasing appearance, butserves to comtially uniform diameter, stones ofg'approxi pensateexpansion and contraction, and tend g, mately two inches in diameterhaving given to heal or "fill cracks. satlsfactory results; however, theinvention I mmous filler which not only makes a smooth preferable to usecrushed stonesof 's'ubstan- 100 It is especially the aim of theinvention to is not to be limited to the size of thesestonesg- I em loy'irregular shaped stones or crushed It is highly desirable that stonesoi'gjirocks 51 V I0 roc which when imbedded'in close relation ofirreghlar shape be used so that when they in the supporting'course,,will, owing to their. are em edded, as is'shown in Figs.5:}3and irregularities overhang and interlock with 6, they will overhangor interlock, thus'holdeach other, thus tendin to prevent relative ingeach other against relative vertical disvertical displacement, -tereby'making for a placement These stones are placed .prefer- 11 ably ina single la er and as close together A construction desl ed to carry outthe as is practical wit out piling oneupon the other. This layer ofstones is then lightly tamped or rolled so that the stones will becu'rely anchored and fastened in the foundation when the concrete sets.When the stones 13 have thus been embedded in the green concrete thoseportions of the stones embedded in the concrete will be closelypositioned to one another and, in some instances, they might be inactual contact. In actual practice, however, it has been found that themortar of the concrete, being more or less plastic, finds its waybetween thesurfaces of juxtaposed stones so that instead of the stonesactually contacting with one another they are somewhat spaced apart byan in tervening film of the mortar. Y

It has been the practice in building pavements to use small stones orcrushed rocks as a bonding means between two courses, but

a such rocks or stones were not spread in close relation, but scatteredand were covered with a top la er or course several inches thick.

It wi 1 be seen that the projecting upper portlons ofthe stones willprovide a substantially continuous layer which will be rou h and an ularand composed almost entire y of bar durable wear-resisting rocks. After,the concrete has set, the surface of this wear layer is swe t clean toremove loose particles of stone, irt, or other forei materials, andthere is then applied to t e said layer a filler 14 to fill theinterstices or voids flush with the highest points of the roiectmgportions of the stones While the ig est oints-of the stones may becovered by the tier, particularly where it is fluent, ller is applied tofill the voids enough.

only an roduce' .a surface substantially flush with t e hi hest pointsof the stones. 'By this method on y about one-tenth the quantity ofmaterial is used for the filler, per square yard, .as' is.. used it: theusual top layer-which s bonded-to the under layer by stones, such asi's'fshownain the patents- Lake 507,683, issued, Qcto'ber 31, 1893, anWarren 916,070, issued March 23, 1909. It is preferable to use abituminous composition which has been brought to the propertemperature-to insure an even distribution and in such quantity thatafter being loaded with fine mineral aggregate, will completely fill allinterstices and surface voids.

After this ste clean, coarse sand, stone screenings, or 0t er suitablematerial in sufficlent quantity is spread over the layer 14. q- Thesurface may be lightly rolled or otherwise treated in accordance withthe practice in this art.

A pavement constructed in accordance with my invention will i have manyadvantages and will tend to eliminate most of the difiiculties andcauses of failure heret0- fore encountered in the construction of suchlayer composed of hard, dura 1e and tough stones, firmly anchoredagamstcreeping or lateral displacement. The weight of trailic will at alltimes rest directly on the tops of the stones rather than upon theplastic filler, the stones being in such close relation that severalwill sustain the load of the average motor vehicle tire, thus overcomingthe disastrous results which occur where the load is carried by abituminous top layer. My pavement will possess a great advantage ,overconcrete pavement, as ordinarily constructed, because the mortar whichnecessarily comes to the surface of a concrete pavement, due to thesinkingof the coarse ag regate therein, is not capable of withstandingabrasion, but functions merely as a bond or cement, and in my avementthere is no such top mortar expose to wear.

A pavement constructed in accordance with my invention, will, it isbelieved, possess greater solidity, continuity and cohesion than thosepavements in which two dissimilar layers are merely bonded togetherby'stones or rocks. It will, of course, be apparent that the bituminousfiller will. add

protect the projectingportions of the stonesfrom being broken off,cracked, or chipped. The stones overhangin and interlocking, as is shownin 'Figs. 5 and 6, will not be easily dislodged, yet they will sustainthe maximum wear and tear upon the pavement.

This application is filedas a continiiation in art of application,Serial No. 144,794.

arious c aiiges in the size and shape of the difi'erent parts, as Well'as modifications and alterations, may be made within the scr$l of theappended claims.

at I claim, is: .1. A avei'nent consistin of a concrete foundation, awear la er 0 relative] lar stones or rocks embe ded partially in saidfoundation with their upper portions protruding from said foundation inclose relation to form a wearing surface. whereby a plurality ofjuxtaposedstones or rocks will substantially simultaneously engage thethread of a vehiclewheel passing over'the same, and a fillerdeposited inthe voids between the portions of the rocks. or stones lar of a concretein said trudin therefrom to form a wearing surface, t e embedded portionof each stone or rock having an interlocking relation with another stoneor rock positloned next adjacent thereto, and a filler deposited in thevoids between the protruding upper portions of the stones or rocks.

3. A pavement consisting of a concrete foundation, a wear layer ofrelatively large stones or rocks embedded partially in said foundationwith their upper portions protruding therefrom to form a wearingsurface, the embedded portion of each rock being closely positioned toand adapted to receive lateral support from the stones or rockssurrounding the same, and a filler deposited in the voids between theprotruding upper portions of the stones or rocks.

4. A pavement consisting of a concrete foundation, a wear layerconsisting of a single course of relatively lar e stones or rocksartially embedded in sai foundation with t eir upper portions rotrudinfrom saidfoundation in close re ation to orm a wearing surface, theembedded portion of each stone or rock having an interlocking relationwith another, stone or rock p081- tioned next adjacent] thereto and theembedded portions of each rock being closely

